Above all else: be useful. Give them something they can use, do, have fun with — something they couldn't get from anyone else. Be a font of information. Be an indespensible resource that helps them make connections with each other around your content.
Be honest about who you are. If you participate in or maintain a social media site for the University, clearly state your affilation. Never hide your identity for the purposes of promoting the University of Rochester on blogs or on social sites.
If you create an institutional social media channel, note in the description, profile or bio that it is the official presence of your department in that channel.
If you create a personal social media channel -- such as a blog or a Twitter account -- and you identify yourself as a member of the University of Rochester community, please clarify that you are sharing your views as an individual, not as a formal representative of Rochester. For example, a common practice is to include a disclaimer on your profile or site such as: "The views expressed on this [blog, website] are mine alone and do not necessarily reflect the views of the University of Rochester." This is particularly important if you are a department head, faculty member or administrator.
If you set up a channel through which people can communicate with you, don't be surprised when they do. For example, someone may ask a technical support question over Twitter, or a question about an upcoming event on Facebook. You cannot create this forum and then abandon it or say, "we only take questions about upcoming events at our box office phone number during business hours."
If someone asks a question via a Facebook page or Twitter account, they do not expect to wait days for a response. If you don't know the answer to a posted question, don't be afraid to say you're looking into it. Depending on the size and activity level of your community, you may need to be be prepared to monitor the site in the evenings and on weekends.
Start thinking in real-time. For example, if you host a student event on Friday, you will get much better response and be a more valued contributor to your community if you post photos of that event to Facebook or Twitter or Flickr on Friday rather than waiting till Monday.
Social media is conversational. It is OK to be friendly, funny, and personable in tone, while still being professional and helpful. Don't talk down to your audience or use an "institutional tone" or jargon they do not share. Start conversations. Ask questions. Laugh at jokes. But if if you are not a 20-year-old, don't try to sound like one when you post. Be yourself.